fix for immobilizer issue? (3 Viewers)

[Kevin Johnson]

Just wanted to give you all a huge Thank You!!! Got stuck up at a ski hill in Flagstaff on Friday. We're full time on the road and I was pretty much screwed. Had the truck towed to a local dealer. The next day the dealer tells me it needs a new ECU and new keys. $3500!!! Went out to the parking lot, jumpered the relay and the immobilizer disabled, the truck started, and I was able to get back to camp 300 miles away. Thank you Thank you Thank you!!!

You should have seen the look on the Service Managers face. Priceless.

 

[Unca Charlie]

My 99 LC went south, and nothing works. Tried all the things in these 9 pages. Bought my 99 LC with 95k 6 years ago, now has 156k. 3 years ago my spare key stopped working. swapped out the other spare and it worked fine. Then they both started working fine for the last 3 years. Yesterday nothing. My wife drove the other key to where I was, and it started fine. Went to the hardware store and nothing.

Fiddled with the battery cables and fuses. Nothing. 30 minutes go by. I finally punched the ignition (without the key in it!) and the light stopped blinking and I drove home. Then right back to a dead LC. I tried all the things listed. Nothing. The light keeps blinking. Toyota guy says it might be the key fob? That doesn't make sense but I'll replace that little battery tomorrow.

 

[Unca Charlie]

Onw more thing. When is the ^%$%$ security light supposed to stop blinking? When I get in the car? When I crank the ignition? When Halley's Comet comes back?

 

[drjman]

Onw more thing. When is the ^%$%$ security light supposed to stop blinking? When I get in the car? When I crank the ignition? When Halley's Comet comes back?

The moment you put the key into the ignition. It's a proximity thing and contact thing inside the ignition. Does not need to be turned.

Did you try the direct jump from the 20amp to the feed to the immobilizer? That's a sure fire way to to see if something in between (20a to relay, relay working/not, relay supplying power to immobilizer/CPU) the jumps is messed up. It's also handy to have a jump cable in case you need to bypass everything just to get home. Don't drive with it jumped permanently, it will drain your battery. That's why there's a relay in there.

It's definitely possible that your fob is not working properly, but I can't remember a thread or multiple examples of that being the main issue. If it doesn't look broken and hasn't been submerged, it just works.

 

[Unca Charlie]

The moment you put the key into the ignition. It's a proximity thing and contact thing inside the ignition. Does not need to be turned.

Did you try the direct jump from the 20amp to the feed to the immobilizer? That's a sure fire way to to see if something in between (20a to relay, relay working/not, relay supplying power to immobilizer/CPU) the jumps is messed up. It's also handy to have a jump cable in case you need to bypass everything just to get home. Don't drive with it jumped permanently, it will drain your battery. That's why there's a relay in there.

It's definitely possible that your fob is not working properly, but I can't remember a thread or multiple examples of that being the main issue. If it doesn't look broken and hasn't been submerged, it just works.

Welllll, that is a problem The fob looks like it sat in the sun for about 6 years. It has disintegrated , but it locks and unlocks the doors with the help of some electrical tape. The key fell off the fob after about 3 months, but like I said, it hasn't affected the starting till now. And I don't think I need the fob. The chip is in the key, right?

 

[drjman]

Welllll, that is a problem The fob looks like it sat in the sun for about 6 years. It has disintegrated , but it locks and unlocks the doors with the help of some electrical tape. The key fell off the fob after about 3 months, but like I said, it hasn't affected the starting till now. And I don't think I need the fob. The chip is in the key, right?

I might be getting this wrong, because I have a LX. My key is a fob. Buttons and electrics are all together. If you have a plain key with plastic toyota emblem, and a separate door lock fob, that's a different story. I'm not sure how those work. sorry.

 

[Unca Charlie]

I got replacement keys, and kept the fob. And I didn't need the fob to start the cruiser. I'm gonna replace the fob battery at this point as I just want to eliminate the obvious. Otherwise, I got nothing. Changing the fuse box sounds like a bitch but I may have to do that,

 

[ScubaJon]

the chip is in the fob part of the key and it does not need a battery to work it just needs to be within an inch or so of the ignition ring.

 

[spressomon]

I got replacement keys, and kept the fob. And I didn't need the fob to start the cruiser. I'm gonna replace the fob battery at this point as I just want to eliminate the obvious. Otherwise, I got nothing. Changing the fuse box sounds like a bitch but I may have to do that,

Same here: G-damn I don't want to deal with swapping in another fuse box; IIRC @beno informed me last year Toyota has discontinued the fuse box for early UZJ100s. But pulled the dreaded P1600 code this week...but Jackson aka Medtro sent the fused wire ready to install as a work around for supplying terminal E with another 12v source. Will know in a few days...

 

[Unca Charlie]

Very nice rig, spress. Who or what is Medtro? I need one of those fused wires.

 

[drjman]

I picked up a used fuse box from a junk yard for $75. Fixed all my issues with immobilizer and P1600 code. I'd hunt for something like that. New is $650

 

[Unca Charlie]

Well, to update y'all, I talked to a mobile locksmith who said he has been getting more and more calls for 100 series LCs. He said that more often than not, and according to my symptoms, the problem is the signal amplifier in the ignition. Not that big a deal to take out, but Toyota doesn't make that part anymore (like my %^@#^% rear tailgate wing that I broke moving my daughter) and the only alternative is a used one. Meaning the used one stands a pretty good chance of failing soon as well.

He said he can reflash the ECU and if I take it out and bring it to him, it'll be $250.00.

Not thrilled about it, but at least i KNOW this won't happen again. Thanks to you guys for your help.

 

[Mauser]

Well, to update y'all, I talked to a mobile locksmith who said he has been getting more and more calls for 100 series LCs. He said that more often than not, and according to my symptoms, the problem is the signal amplifier in the ignition. Not that big a deal to take out, but Toyota doesn't make that part anymore (like my %^@#^% rear tailgate wing that I broke moving my daughter) and the only alternative is a used one. Meaning the used one stands a pretty good chance of failing soon as well.

He said he can reflash the ECU and if I take it out and bring it to him, it'll be $250.00.

Not thrilled about it, but at least i KNOW this won't happen again. Thanks to you guys for your help.

What is rhe part number on your ecu? Are the last numbers 60610? If they are I can send you a virginized ecu to see if that is the problem. If it fixes your problem we can work somerhing out

 

[Unca Charlie]

What is rhe part number on your ecu? Are the last numbers 60610? If they are I can send you a virginized ecu to see if that is the problem. If it fixes your problem we can work somerhing out

Nope. It is 60261. Thanks, though. I'm about 99% sure it isn't the fuse box because none of the fixes described, and I tried most of them, did anything. It randomly started yesterday when my wife fiddled with it, but I couldnt' recreate what she did, and I replaced the key fob battery and that did no good. I guess I could start punching the glove box to see if that works . . .

But as it is, I'm spending the $250 to get it reflashed and dealt with. If the fuse box goes after this, well, I'm selling . . . jk

Do you have a tailgate wing by any chance?

 

[spressomon]

Update: I received the 2nd part of the bypass kit from @medtro (thanks for yet another bailout Jackson!), installed it in all of 2-minutes and so far, with an 80-mile test drive, the P1600 is cleared and hasn't come back.

 

[lexs470]

Update: I received the 2nd part of the bypass kit from @medtro (thanks for yet another bailout Jackson!), installed it in all of 2-minutes and so far, with an 80-mile test drive, the P1600 is cleared and hasn't come back.

I have the same scenario with the kit throwing the P1600 code. what is the second part of the kit you received ? is it getting power to terminal E from a different source ? if so where is it getting the power from if you would kindly share. thanks much !

 

[spressomon]

^ contact Jackson aka @medtro for all the details...we're traveling backcountry and limited cell

 

[Unca Charlie]

Well, just to finish this saga out, for me anyway, the locksmith guy told me that the 1999-2000 LC ECUs cannot be flashed to immobilize the immobilizer. He ended up coming out in his office on wheels. and checked the signal amplifier in the ignition. The electrical system checked out fine. I reinstalled the ECU and that checked out fine as well. It turns out both my keys had failed. Good news for me as the keys were only $120 for 2 of them. No house call charge as well.

**** Still looking for a replacement rear wing ****

 

[LX 470 Lady]

You can change the EFI fuse in the relay/fuse box under the hood. Change the fuse even if it looks good.

I changed my fuse today. IT WORKED!! "My baby " STARTED RIGHT UP!! THANX!!

 

[DMX84]

I wanted to add that my ‘98 started this intermittent starting issue quickly escalating to leaving me stranded at work. I pulled the fuse it looked a little dirty and figured reseating it would make it fire..... wrong. But it fooled me as the relay was working - they must be on a different circuit? Anyway I used spray electrical contact cleaner and a new 20a fuse and it seems to have fixed my issue.
Picture of the original fuse, showing how oxidized it was- definitely looks worse with 5x magnification!
Cheers.